Safety projectile for underwater detonation

ABSTRACT

The projectile has a spring urged firing pin held out of contact with the primer by a first locking ball engaging a release member spring urged into contact with a fluid pressure responsive piston designed to axially move the release member out of engagement with the locking member against the force of the spring upon the occurrence of an external pressure above a predetermined pressure, which pressure reaches the piston through a conduit having therein a normally open valve closed by the tubular wall of the cartridge case. An additional locking ball is held in its position blocking movement of the firing pin by means of a safety member spring urged out of engagement with the ball and held against the force of its spring by the cartridge case.

United States Patent inventors Heinz Gawlick;

Rudolf Stahlmann, both of Furth, Germany Appl. No 726,723 Filed May 6, 1968 Patented June 8, 1971 Assignee Dynamit Nobel Aktiengesellschaft Troisdorf, Germany Priority May 5, 1967 Germany B53004 SAFETY PROJECTILE FOR UNDERWATER DETONATION l6 Claims, 1 Drawing Fig.

[56] References Cited UNITED STATES PATENTS 3,048,111 8/1962 Bakeretal 102/81X Primary Examiner Samuel W. Engle Assistant Examiner-Jerald J. Devitt Attorney-Craig, Antonelli, Stewart and Hill ABSTRACT: The projectile has a spring urged firing pin held out of contact with the primer by a first locking ball engaging a release member spring urged into contact with a fluid pressure responsive piston designed to axially move the release member out of engagement with the locking member against the force of the spring upon the occurrence of an external pressure above a predetermined pressure, which pressure reaches the piston through a conduit having therein 3 normally open valve closed by the tubular wall of the cartridge case. An additional locking ball is held in its position blocking movement of the firing pin by means of a safety member spring urged out of engagement with the ball and held against the force of its spring by the cartridge case.

PATENTEU JUN 81911 3583320 u N U1 NE 29 INVENTORS HEINZ GAWLICK RUDOLF STAHLMANN BY M 8 ATTORNEYS SAFETY PROJECTILE FOR UNDERWATER DETONATION BACKGROUND OF THE INVENTION There are many applications for a projectile to be detonated underwater, particularly of a caliber to be fired from a pistol or other similar hand device. It is desirable to have the detonator device automatically respond upon reaching or exceeding a predetermined ambient pressure, but which is completely safe in transport and handling, at least until this pressure is attained.

SUMMARY OF THE INVENTION The above desired characteristics are met by the projectile of the present invention having an axial bore providing a chamber containing a relatively movable primer and firing pin spring urged into engagement by a spring and held apart by two locking balls, disposed in radial bores communicating with the chamber, which locking balls are respectively held in their locking position by means of an axially movable release member and an axially movable safety member. An ambient pressure responsive piston is mounted in the projectile to remove the release member out of engagement with its ball against the force of a spring.

With such an arrangement, the desired detonating pressure may be accurately predetermined by an appropriate selection of the spring force acting upon the release member and the effective pressure area of the piston that is in communication with the ambient pressure external of the projectile by a suitable conduit.

A further advantageous feature of the present invention is obtained by a safety provision employing a normally spring biased opened valve in the conduit that is held in its closed position by means of a removable member on the exterior of the projectile, particularly the tubular wall of the cartridge case. This valve feature assures that detonation will not occur if the predetermined pressure is unintentionally exceeded at least until the removable member has been stripped off.

A further safety feature is provided by the present invention with respect to the second locking ball being held in its locking position by means of an axially movable safety member that is purely mechanically controlled. A removable member on the exterior of the projectile holds the safety member in its position engaging its locking ball against the force of a spring tending to move it out of engaged position, which removable member is preferably the cartridge case bottom piece or tubular wall. As soon as the removable member or cartridge case is removed from the projectile, the detonator will be armed.

It is possible to so dimension the pneumatic and mechanical safety provision so that they will both be effective to retain the detonator in its unarmed state at least until the projectile has left the barrel of the firing device, by employing the gas pressures within the barrel and the barrel wall for holding the valve or safety member and safety member, respectively, in safety position.

BRIEF DESCRIPTION OF THE DRAWING Further objects, features and advantages of the present invention will become more clear from the following detailed description of a sonar signaling cartridge according to a preferred embodiment illustrated in detail in the accompanying drawing, which shows a partial axial cross-sectional view through a projectile within a cartridge case.

DETAILED DESCRIPTION OF THE DRAWING As shown in the figure, the projectile is made up of a plurality of axially jointed segments, which is advantageous in the manufacture with respect to the forming of the various size bores. A central axial bore 23 forms a chamber within the support or detonator body 24 of the projectile. Within the chamber 23, there is an axially movable firing pin element 1 having a firing pin 25, which element is under the constant bias of compression spring 17 also within the chamber 23. The firing pin element 1 is provided with a central annular constriction 26 receiving therein two diametrically opposed locking balls 2, which balls are disposed in the radial bore or passage 27 so that in their illustrated position they prevent forward movement of the firing pin element 1 under the influence of its spring 17. The left-hand locking ball, with respect to the illustration, is maintained in position by engagement with a release member or pin 4 held in its illustrated position by the coil compression spring 9. The other locking ball is held in its illustrated position by means of a safety member including the axially movable pin 3 that is held in its illustrated position against the force of its compressed coil spring 5.

The release member 4 is drivingly engaged by a pressure responsive piston 10 axially slidably mounted within a correspondingly shaped cylinder of the projectile body. The lower effective pressure surface of the piston 10 is in fluid communication with the exterior of the projectile detonator body 24 by way of the conduit 14 and is seated on the surface 11 of the part 12 of the detonator body 24. The safety member 3 includes an axially movable safety pin 6 held in its illustrated position by means of the blocking ball 7 radially engaging the tubular wall 8 of the cartridge case. Also, the cartridge case tubular wall 8 holds the valve 15 in its illustrated position sealingly engaging the seat 16 of the conduit 14 against the force of its spring 13 biasing it towards its open position.

The cartridge case includes a bottom piece 28 having therein a primer cap 29 and a propellant charge 13. At the other end of the cartridge, within the detonator body 24, there is provided a primer composition element including a case 18 having therein the primer composition 30 opposite from and aligned with the needle 25 within the chamber 23, which primer composition element 18 is fixedly mounted with respect to the detonator body 24 by means of the threaded tubular plug 20 provided with a central axial detonator channel 19. The sound-producing charge 31 is arranged forward of the plug 20 within the tubular projectile casing 21 to form the forward portion of the projectile, not illustrated in its entirety. A detonator channel 22 is provided concentrically within the charge 31 by the lining 32.

Upon firing the cartridge, the propellant gases evolving from the ignition of the propellant charge 13 eject the projectile detonator body 24 as a unit together with the various detonator parts and the sonar signal charge from the cartridge case tubular wall 8 and subsequently from the barrel of the firearm. The pressure of the propellant gases flowing along the outside of the detonator body 24 within the barrel of the firearm press the valve 15 radially inwardly against the seat 16 to prevent any substantial pressure rise within the conduit 14.

With the above-described ejection of the detonator body 24 from the tubular wall of the cartridge case, the blocking ball 7 will move radially outwardly into engagement with the barrel of the firearm, with the corresponding elements designed to either thereby release the safety member 3, 6 or continue to block its rearward movement until the ball 7 has moved further radially outwardly after ejection of the detonator body 24 from the barrel of the weapon. Depending upon the design of the effective rearwardly facing pressure surface of the safety member 6 and the spring 5, the propellant gas pressure may or may not be sufficient to hold the safety member 6 in its illustrated position while the projectile is still within the barrel of the firearm. In any case, after the detonator body 25 has been ejected from the barrel of the firearm, the valve 15 will be ejected radially outwardly by means of the spring 33 to establish communication between the lower effective surface 34 of the piston 10 with the pressure outside of the projectile.

With the pressure piston 10 firmly engaged against the surface 11 of the part 12 under the bias of the spring 9, the spring 5 axially moves the pins of the safety member 3, 6 rearwardly, after the above-described firing; the pin 6 is ultimately ejected rearwardly out of the detonator body 24 with the pin 3 moving rearwardly a sufficient distance to release the associated locking ball 2 under the influence of the spring 5. Thereby, the additional mechanical safety unit is unlocked, that is, the mechanical safety mechanism is released. Since the projectile travels at a relatively great velocity and the above-described sequence of movements requires a finite time for release, this ensures a mechanical safety of the projectile detonator mechanism over a certain distance after the projectile leaves the barrel, if desired, which may be predetermined and chosen as desired by corresponding dimensioning and selection of the various components.

At the end of the trajectory of the projectile when the projectile enters the water, the pressure corresponding to the water depth will be effective upon the surface 34 of the piston by way of the conduit 14, the valve having been ejected previously. As soon as the force produced thereby on the piston 10 exceeds the oppositely directed force of the compressed spring 9, the piston 10 will be axially displaced forwardly; this displacement of the piston 10 will also move the release member or pin 4 forwardly against the bias of the spring 9 until the release member 4 is moved to a position where its annularly constricted area 35 is radially opposite the locking ball 2, thus permitting the locking ball 2 to move radially outwardly to at least a limited degree sufficient for releasing the firing pin element 1. After the above-described release of the firing pin element 1, it will be displaced axially forwardly by the compressed spring 17 toward the primer composition element 18 for ignition of the primer composition 30, which ignited composition will in turn ignite the sonar signal charge 31.

By appropriately dimensioning and selecting the pressure piston effective area 34 facing the conduit 14 and/or the force of the spring 9, the predetermined pressure required for triggering the projectile detonator device may be chosen as desired.

The principles and structural subcombinations of the above specifically described sonar signaling projectile and cartridge case may be employed with materially different devices and with variations according to the broader principles of the present invention, such as by providing an integral construction of the pins 3 and 6 or the pin 4 and piston 10. Additional variations, modifications and embodiments are contemplated within the spirit and scope of the present invention as defined by the following claims.

We claim:

1. A projectile having a chamber; a firing pin element and a primer composition element spaced in aligned position within said chamber, one of said elements being mounted for displacement relative to said projectile into contact with the other of said elements, and the other of said elements being relatively fixedly mounted with respect to said projectile; said projectile having means constantly biasing said one element toward said other element; a passage opening into said chamber; a locking member mounted for movement within said passage between a first position extending into said chamber to block movement of the one of said elements into engagement with the other of said elements against the force of said biasing means and a second position to allow movement of said one of said elements forwardly into engagement with the other of said elements under the influence of said biasing means; a release member having one position normally engaging said locking member and holding it in its first position, said release member being mounted for movement with respect to said locking member to another position to allow movement of said locking member to its second position; said release member having means constantly biasing it into said one position and fluid pressure responsive means for moving it into its another position in response to ambient pressure at least as great as a predetermined pressure substantially above atmospheric; and an additional independent locking member mounted for movement between a first position extending into said chamber to block movement of the one of said elements into engagement with the other of said elements and a second position to allow movement of said one of said elements into engagement with the other of said elements.

2. The projectile according to claim 1, wherein said locking member moves radially between its two positions; said release member moves axially between its two positions; said fluid pressure responsive means includes a piston-cylinder and a conduit establishing fluid communication between the exterior of said projectile and only one effective side of said piston; each ofsaid biasing means being a spring.

3. The projectile according to claim 2, including a valve serially arranged in said conduit and biased towards its open position; removable means on the exterior of said projectile and holding said valve in its closed position against its bias.

4. The projectile according to claim 3, including a safety member having one position normally engaging said additional locking member and holding it in its first position and being mounted for movement to another position to allow movement of said additional locking member to its second position; spring means biasing said safety member into its another position; a blocking member normally engaging said safety member and holding said safety member in its first position against its spring force; and means removably mounted on the exterior of said projectile for holding said blocking member into engagement with said safety member.

5. The device of claim 4, including a cartridge case telescopically receiving said projectile therein and having a forward tubular wall portion constituting at least in part said removable means and said removably mounting means.

6. The device of claim 4, wherein said projectile includes an axially extending blind, rearwardly opening bore receiving said safety member.

7. The device of claim 6, including a cartridge case telescopically receiving said projectile therein and a bottom piece having therein a propellant charge; said bottom piece abutting the rearward end of said safety member in its said one position.

8. The device of claim 3, including a cartridge case telescopically receiving said projectile therein, wherein at least one of said projectile and said cartridge case include charge means for producing a propellant gas; said cartridge case and said projectile forming therebetween a pressure chamber for receiving the propellant gases; said valve having pressure surface means in direct free communication with said pressure chamber for producing a force in reaction to the propellant gases that biases said valve into its closed position.

9. The device of claim 1, wherein said locking member is a ball.

10. The device of claim 1, including a cartridge case telescopically receiving said projectile therein and having a forward tubular wall portion constituting at least in part said removable means.

11. The device of claim 1, including a valve serially arranged in said conduit and biased towards its open position; removable means on the exterior of said projectile and holding said valve in its closed position against its bias.

12. The device of claim 11, including a cartridge case telescopically receiving said projectile therein, wherein at least one of said projectile and said cartridge case includes charge means for producing a propellant gas; said cartridge case and said projectile forming therebetween a pressure chamber for receiving the propellant gases; said valve having pressure surface means in direct free communication with said pressure chamber for producing a force in reaction to the propellant gases that biases said valve into its closed position.

13. The device of claim 1, including a safety member having one position normally engaging said additional locking member and holding it in its first position and being mounted for movement to another position to allow movement of said additional locking member to its second position; spring means biasing said safety member into its another position; a blocking member normally engaging said safety member and holding said safety member in its first position against its an axially extending blind, rearwardly opening bore receiving said safety member.

16. The device of claim 15, including a cartridge case telescopically receiving said projectile therein and a bottom piece having therein a propellant charge; said bottom piece abutting the rearward end of said safety member in its said one positron. 

1. A projectile having a chamber; a firing pin element and a primer composition element spaced in aligned position within said chamber, one of said elements being mounted for disPlacement relative to said projectile into contact with the other of said elements, and the other of said elements being relatively fixedly mounted with respect to said projectile; said projectile having means constantly biasing said one element toward said other element; a passage opening into said chamber; a locking member mounted for movement within said passage between a first position extending into said chamber to block movement of the one of said elements into engagement with the other of said elements against the force of said biasing means and a second position to allow movement of said one of said elements forwardly into engagement with the other of said elements under the influence of said biasing means; a release member having one position normally engaging said locking member and holding it in its first position, said release member being mounted for movement with respect to said locking member to another position to allow movement of said locking member to its second position; said release member having means constantly biasing it into said one position and fluid pressure responsive means for moving it into its another position in response to ambient pressure at least as great as a predetermined pressure substantially above atmospheric; and an additional independent locking member mounted for movement between a first position extending into said chamber to block movement of the one of said elements into engagement with the other of said elements and a second position to allow movement of said one of said elements into engagement with the other of said elements.
 2. The projectile according to claim 1, wherein said locking member moves radially between its two positions; said release member moves axially between its two positions; said fluid pressure responsive means includes a piston-cylinder and a conduit establishing fluid communication between the exterior of said projectile and only one effective side of said piston; each of said biasing means being a spring.
 3. The projectile according to claim 2, including a valve serially arranged in said conduit and biased towards its open position; removable means on the exterior of said projectile and holding said valve in its closed position against its bias.
 4. The projectile according to claim 3, including a safety member having one position normally engaging said additional locking member and holding it in its first position and being mounted for movement to another position to allow movement of said additional locking member to its second position; spring means biasing said safety member into its another position; a blocking member normally engaging said safety member and holding said safety member in its first position against its spring force; and means removably mounted on the exterior of said projectile for holding said blocking member into engagement with said safety member.
 5. The device of claim 4, including a cartridge case telescopically receiving said projectile therein and having a forward tubular wall portion constituting at least in part said removable means and said removably mounting means.
 6. The device of claim 4, wherein said projectile includes an axially extending blind, rearwardly opening bore receiving said safety member.
 7. The device of claim 6, including a cartridge case telescopically receiving said projectile therein and a bottom piece having therein a propellant charge; said bottom piece abutting the rearward end of said safety member in its said one position.
 8. The device of claim 3, including a cartridge case telescopically receiving said projectile therein, wherein at least one of said projectile and said cartridge case include charge means for producing a propellant gas; said cartridge case and said projectile forming therebetween a pressure chamber for receiving the propellant gases; said valve having pressure surface means in direct free communication with said pressure chamber for producing a force in reaction to the propellant gases that biases said valve inTo its closed position.
 9. The device of claim 1, wherein said locking member is a ball.
 10. The device of claim 1, including a cartridge case telescopically receiving said projectile therein and having a forward tubular wall portion constituting at least in part said removable means.
 11. The device of claim 1, including a valve serially arranged in said conduit and biased towards its open position; removable means on the exterior of said projectile and holding said valve in its closed position against its bias.
 12. The device of claim 11, including a cartridge case telescopically receiving said projectile therein, wherein at least one of said projectile and said cartridge case includes charge means for producing a propellant gas; said cartridge case and said projectile forming therebetween a pressure chamber for receiving the propellant gases; said valve having pressure surface means in direct free communication with said pressure chamber for producing a force in reaction to the propellant gases that biases said valve into its closed position.
 13. The device of claim 1, including a safety member having one position normally engaging said additional locking member and holding it in its first position and being mounted for movement to another position to allow movement of said additional locking member to its second position; spring means biasing said safety member into its another position; a blocking member normally engaging said safety member and holding said safety member in its first position against its spring force; and means removably mounted on the exterior of said projectile for holding said blocking member into engagement with said safety member.
 14. The device of claim 13, including a cartridge case telescopically receiving said projectile therein and having a forward tubular wall portion constituting at least in part said removable means and said removably mounting means.
 15. The device of claim 13, wherein said projectile includes an axially extending blind, rearwardly opening bore receiving said safety member.
 16. The device of claim 15, including a cartridge case telescopically receiving said projectile therein and a bottom piece having therein a propellant charge; said bottom piece abutting the rearward end of said safety member in its said one position. 